Electric selective system.



No. '755,127 PATENTED MAR. 22, 19M. J. A'. GEHRUNG.

ELECTRIC SELECTIVE SYSTEM.

APPLICATION FILED PEB. a. 1902.

No MODEL.

UNITED STATES Patented March 2 2, 1904.

PATENT OFFICE.

ELECTRIC SELECTIVE SYSTEM.

SPECIFICATION forming part of Letters Patent No. 755,127, dated March 22, 1904.

Application filed February 8, 1902. Serial No. 93,112. (No model.)

T0 all whom it may concern: Be it known that I, JULIEN AUGUSTE GEH- RUNG, a citizen of the United States of America, and a resident of the city of St. Louis and State of Missouri, have invented certain new and'useful Improvements in Electric Selective Systems, of which the following is a speciication.-

The present invention relates to electric selective systems, and is an improvementupon the invention patented 'to me August 6, 1901, No. 680,036, whereby the principles of operation therein contained are made applicable to the call-bells of party -line telephones and other like uses wherein the individual selectively-actuated devices of the series arearranged at points remote from each other, all

`as will hereinafter more fully appear, and be more particularly pointed out inthe claims.

The accompanying drawing is a diagrammatic view illustrating the application of the present electrical selective system to the callbells of a group of four party-line telephones. In the present invention the electrical selective system which forms the subject-matter of my prior patent, No. 680,036, dated the 6th day of August, 1901, is employed in a modified manner in connection with the series of callbells of a group of party-line telephones to select and ring any particular call-bell-to the exclusion of the others of the series of such call-bells.

In the present improved construction, as-

illustrated in the present drawing, 1 represents a series of individual circuit-closers or sending-keys at the central station and corresponding in number to the number of partyline telephones in the group with which such sending-keys are used. Each sending-key is adapted to send along the marin lineQ an electrical impulse the strength of which differs from the strength of any of the other electrical impulses introduced along the main line by the other sending-keys of the series.

3 is an electrical resistance, preferably in the form of a single elongated resistance-coil, provided at regular intervals along its length with a series of contact-points for contact with the sending keys l aforesaid, so that 'each particular sending-key will introduce a dif-v ferent amount of resistance in the main-line circuit. Accordingly in the construction shown the sending-key 1 to the left will introduce the whole electromotive force of the main-line battery into the main line or circuit, while each succeeding sending-key 1 to the right will introduce a progressively -increased resistance with a lcorrespondingly-reduced amount of electromotive force into the main line or circuit. Y The electromotive force used in the present system will preferably be of the alternating or pulsating order in that the same is best adapted for generating secondary or induced local circuits at the party -line telephones with which to ring the call-bells on such party-line telephones.

4. is the main-line battery,and 5 an electrical current-controller or interrupter 'adapted to change the constant current of said battery into the desired alternating or pulsating current'of the present system. In the general application of the present invention an alter'- nating or pulsating current generator may be substituted for the battery 4 and current controller or interrupter 5 where the particular circumstances may suggest such substitution.

6 represents a series of selective electromag-- nets arranged in pairs at each party-line-telephone station or point and provided with independent armatures 7 In the present system the above-mentioned series of electromagnets 6, as in my former patented construction, will be provided in any usual and suitable manner with progressively varied or diverse strengths or intensities to correspond with the progressively varied ordiverse electromotive strength of the electrical impulses sent along the line by the before-described series of sending-keys at the central station, and such varied or diverse strengths in said windings may be attained either mechanically, by variations in the windings, or by the series of'local and diverse resistances 6 6 6i. (Shown in the drawing.)

8 represents the primary windings of the selective electromagnets 6 and which windings are in circuit with the main line in any usual manner, preferably by branch circuits of the same, as shown in the drawing.

9 represents a series of secondary windings IOO or induction-coils arranged within the iniiuence of the primary windings 8 of the selective electromagnets and in which secondary windings under the conditions hereinafter described secondary currents are induced for use in operating the series of call-bells used in connection with a series of party-line telephones.

10 and 11 are the opposed contact fingers and points of a series of selective circuitclosers, which are automatically operated in an interdependent manner by the series of selective electromagnets 6, and to this end the contact-finger 10 of each individual circuit-closer will be carried by the individual armatures 7 of one of the pair of selective electromagnets at the particular local or party-line station, while the contact-point ll will be carried by the individual armature of the other selective electromagnet of the aforesaid pair. It is material to the operation of the present system that the selective electromagnets comprising the described pair dier in their electromotive strength or intensities in the manner hereinbefore described, and in the present system, while each individual selective electromagnet 6 may have a varied or diverse and different electromotive strength, it is preferable to have the selective electromagnet operating the contact-point l1 of one circuit-closer of the same electromotive strength as selective electromagnet operating the contact-linger 10 of the next adjacent circuit-closer of the series and in like manner through the entire series of such selective electromagnets in that with such arrangement and a given electromotive force used upon the main line a greater difference can be made between the different operating electrical impulses employed in the system, with a consequent increase in accuracy and certainty of operation. Another advantage resulting from the described arrangement is that the individual call-bells or the like can be arranged in locations remote from each other, and therein differs from the particular system illustrated in my former patent, No. 680,036, in which the type-bars or like recording devices have an adjacent relation to each other.

In my preferred construction of the abovementioned selective circuit-closers shown in the present drawing each circuit-closer will comprise an arrangement of parts as follows:

10 is an insulated and movable contact-iinger pivotally connected to the armature 7 of a selective electromagnet and electrically connected to one terminal of the induced local circuit, hereinafter more fully referred to. 1l is an insulated contact-point carried by the armature of a companion selective electromagnet and electrically connected to the other terminal of the induced local circuit above referred to, thearrangement being such that under certain conditions only the free end of the movable linger 10 will contact with the point 11 and close such induced local circuit upon the individual call-bell to actuate the same.

12 represents aseries of call-bells, each one of which is individual to its party-line telephone and each one of which has its individual induced local operating-circuit. rl`he said local circuit in addition to such call-bell embraces an individual selective circuit-closer above described and the secondary winding 9 of the particular pair of selective electromagnets at the described local point or station.

13 represents aseries of stationary fulcrumblocks, to which the movable contact-lingers 10 are fulcrumed at one end and which are adapted to normally hold such contact-fingers out of contact with the contact-points 11.

In the operation of the present system with the sending of an electrical calling impulse along the main line from the central station by means of a selected calling-key 1 the electrical impulse will pass along the main line and along the various branch circuits thereof embracing the different selective electromagnets, operating all of such electromagnets which have a lesser resistance until an electromagnet is reached which is incapable of actuation by the strength of such particular impulse, and in consequence the armature of such last-mentioned electromagnet will remain inactive with the contact-point 11, carried thereby in the path of the movable contact-finger l() of the next preceding and weaker selective electromagnet, so that with an active movement of such contact-finger the induced local circuit will be closed upon the particular party-line call-bell to cause the same to ring.

Having thus fully described my said invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In an electric selective system, the combination of a main line, means for sending varied or diverse electrical impulses along the main line from the central station, a series of selective electromagnets in circuit with the main line, and arranged in pairs with different electromotive intensities, one of said pair of electromagnets having a like electromotive intensity to an electromagnet in a preceding pair, and the other electromagnet having a like electromagnetic intensity to an electromagnet in a succeeding pair, a series of circuit-@losers interdependently controlled by said selective electromagnets, a series of signal devices arranged in locations remote from each other, and aseries of local circuits, each one of which embraces a signal device, and a selective circuit-closer, substantially as set forth.

2. In an electric selective system, the combination of a main line, means for sending varied or diverse electrical impulses along the main line from the central station, a series of selective electromagnets in circuit with the main line and arranged in pairs of different electromotive intensities, one of said pair of IOO IIO

closers interdependently controlled by saidselective electromagnets, one contact-finger of each circuit-closer being controlled by one selective electromagnet and the companion contact-point by the next adjacent selective electromagnet, the said contact-lingers comprising bars ulcrumed at one end to stationary brackets and pivotally connected at their middle with armatures of their selective electromagnets, a series of signal devices arranged in locations remote from each other, and a series of local circuits, each one of which embraces a signal device and a selective circuit closer, substantially as set forth.

3. In an electric selective system, thecombination of a main line, means for sending varied or diverse electrical impulses along the main line from the central station, a series of selective electromagnets in circuit with the main line and arranged in pairs of different electromotive intensities, one oi' said pair of electromagnets having a like electromotive intensity to an electromagnet of a preceding pair, and the other electromagnet having a like electromagnetic intensity to an electromagnet in a succeeding pair, a series of circuitclosers interdependently controlled by said selective electromagnets, a series of secondary windings arranged within the influence of the primary windings of said electromagnets, a series or' signal devices arranged in locations remote from each other, and a series of local circuits each one of which embraces a signal device, a secondary winding and a selective circuit-closer, substantially as set forth.

4. In an electric selective system, the combination of a main line,- means for sending varied or diverse electrical impulses along the main line from the central station, a series of selective electromagnets in circuit with the main line, and arranged in pairs with different electromotive intensities, a series oi' vcircuitclosers interdependently controlled by said selective electromagnets, aseries of secondary windings arranged within the influence of theY primary windings of said electromagnets, a series of signal devices arranged 1n locations remote from each other, and a series of local circuits, each one of which embraces a signal device, a secondary winding and a selective circuit-closer, substantially as set forth.

5. In an electric selective system, the combination of a main line, means for sending varied or diverse electrical impulses along the main line from the central station, a series of selective electromagnets in circuit with the main line, a series of circuit-closers interdependently controlled by said selective electromagnets, one contact-linger of each circuitcloser being controlled by one selective electromagnet and the companion contact-point by the next adjacent selective electromagnet, the said contact-lingers comprising bars fulcrumed at one end to stationary brackets and pivotally connected at their middle with armatures of their selectiveelectromagnets, a series of secondary windings arranged within the iniiuence of the primary windings of said electromagnets, a series of signal devices arranged in locations remote from each other, and a series of local circuits, each one of which embraces a signal device, a secondary winding and a selective circuit-closer, substantially as set forth.

Signed at St. Louis, Missouri,- this 3d day of February, 1902.

JULIEN AUGUSTE GHRUNG. 

